Pulverized coal burner



June 8, 19 37. I I 'L. SHUMAN 2,083,126

PULVERIZED COAL BURNER Filed June 10, 1933 2 Sheets-Sheet l fi L a 8 Q LL //VVEA/7'0/? mm sss;

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June 8, 1937. L. SHUMAN 2,083,126

PULVERIZED COAL BURNER Filed June 10, 1933 2 Sheets-Sheet 2 W CBSW Patented June 8, 1937 UNITED STATES PATENT OFFICE 7 Claims.

Objects of the present invention are to provide simple, eflicient, reliable and inexpensive means for burning pulverized coal, or coal dust for house heating purposes or in other small plants, and to provide for the convenient replacement of parts.

Other objects of the invention will appear from the following description.

The invention also comprises the improvements to be presently described and finally claimed.

In the following description reference will be made to the accompanying drawings forming part hereof and in which Figure l is a side elevational view, principally in section, illustrating apparatus embodying featgres of the invention with gears and shafting omitted.

Fig. 2 is a similar View showing an end elevation the hopper and mixing chamber being shown in section.

Fig. 3 is a sectional view taken on the line 33 of Fig; 1. v

Fig. 4 is a View with parts broken away of the discharge end of the conduit.

Figs. 5 and 6 are views showing parts illustrated in Fig. 1 and embodying modifications, and

Figs. 7 and 8 illustrate other modifications.

' Referring to they drawings, I is an ignition chamber, and it is shown as provided with an opening 2 for the accommodation of a pilot light. Ordinarily the ignition chamber I may be mounted through the front wall 3 of a furnace or heater so as to discharge into the combustion chamber. 4 is a hopper for coal dust or finely pul- 35 verized coal. The hopper 4 is provided witha regulatable gate 5 in one of the side walls of its discharge end. at the exit of the hopper, and it is provided with a regulatable air inlet 1. 40 arranged at the exit of the mixing chamber. 9

is a conduit at the exit or discharge side of the blower, and it communicates with the ignition chamber l. The conduit 9 includes a regulatable air inlet whirler ID. The whirler 10, Fig. 3 is 45 provided with openings II, and inturned tongues [2. The cap I3 is a meansfor co-vering and uncovering portions of the openings II. It is a jet device for discharging air through the whirler. At the end of the conduit 9 and mounted on 50 the air jet device M are vanes 9 which are slanting or warped. l 5 is a cylindrical rotatable feeder at the exit of the hopper, and it may be covered with rubber or some like material to which the finely divided or pulverized fuel adheres and by 55 which the fuel is carried out of the hopper past 6 is a mixing chamber arranged.

8 is a blower or fan the gate 5, which can be set to increase or diminish the quantity of fuel so carried out. [6 is a rotating brush, and it serves to remove powdered fuel from the surface of the cylinder l5 and to scatter it in the mixing chamber.

Although pulverized fuel is rather coherent, nevertheless the described feeding and distributing means satisfactorily distribute it into the air current passing from the inlet 1 through the mixing chamber even in quite small quantities, for 10 example, as little as from one to three pounds per hour. The mixture of air and coal dust is drawn into the blower and further mixed and then dischargedthrough the conduit 9 and whirler l0 into the ignition chamber. Additional air 15 is introduced through the jet l4 and through the openings in the whirler. In the ignition chamber combustion is started, for example, by a pilot light, not shown, and the combustion is complete and satisfactory. 0

One means of regulation is tochange the speed of the blower 8 driven by the motor I1, and the motor is shown as geared to a counter shaft l8 which drives the feeder l5 through worm gear l9, and which also drives the rotating brush it through gearing 20.

The construction and mode of operation of the modifications shown'in Figs. '5 and 6 are as above described except that'use is made of a scraper 2| as a means for removing powdered coal from the surface of the cylinder lfi. in the mixing chamber 5. The powdered fuel removed by the scraper falls into or upon a screen basket. In Fig. 5 the basket 22 is mounted upon a spring arm 23 and is agitated by a spoked wheel 24, with the result that the powdered fuel is distributed in the mixing chamber. As shown in Fig. 6, the rotating arms 25 serve the purpose of passing the powdered fuel through'the sieve 28 and into the mixing chamber 6, so that it is mingled with 40 the air current passing through the mixing chamher.

The construction and mode of operation of the modifications shown in Figs. 7 and. 8 are as above described, except that in Fig. 7 the cylin- 4.5 drical feeder is replaced by a, disc or table [5 rotatable about a vertical axis, and in Fig. 8 the cylindrical and table feeders are replaced by an endless belt feeder I5 In "the foregoing description and appended claims the terms coal dust and pulverized coal are used to include coke and any other finely divided solid fuel.

I claim: I

1. In a pulverized coal burner, the combination of, a hopper for pulverized coal having an exit therefrom, a substantially enclosed mixing chamber communicating with the exit of said hopper and provided with a regulatable air inlet and with an outlet for a mixture of coal and air, a drum arranged for rotation in said chamber adjacent the exit from said hopper providing a moving Wall for removing the coal from said hopper, means arranged in said chamber and contacting with said drum adjacent said air inlet to remove coal from said drum and to distribute it in the flow of air in said chamber from said air inlet, and means for rotating said drum.

2. In a pulverized coal burner, the combination of, a hopper for pulverized coal provided with a discharge end having an outlet in one side of said end, a gate arranged to control said outlet, a substantially enclosed mixing chamber communicating with said outlet from said hopper.

and provided with an outlet for a mixture of coal and air and with a regulatable air inlet, a drum mounted for rotation in said mixing chamber beneath said outlet from said hopper and adjacent to said gate and to said outlet, a rotatable brush mounted in said chamber between said air inlet and said outlet for a mixture of coal and air, mechanical means for rotating said brush in contact with said drum to remove coal from said drum and to distribute it in the flow of air through said chamber, and means for rotating said drum.

3. In a pulverized coal burner, the combination of, a hopper for pulverized coal provided with a discharge end having an outlet in one side of said end, a gate arranged to'control said outlet from said hopper, a substantially enclosed mixing chamber communicating with said outlet from said hopper and provided with an outlet for a mixture of coal and air and with a regulatable air inlet, a drum mounted in said chamber for rotation beneath and adjacent. said outlet from said hopper, a scraper for removing coal from said drum, a perforated member mounted in said chamber between said air inlet and said outlet for a mixture of coal and air and beneath said scraper to receive coal removed by said scraper, and mechanical means for agitating coal on said perforated member so as to distribute the coal in the flow of air from said air inlet through said chamber.

4. In a pulverized coal burner, the combination of, a hopper for pulverized coal provided with an outlet, a substantially enclosed mixing chamber communicating with the outlet from said hopper and having a regulatabl-e air inlet therein and having an outlet for a mixture of coal and air therefrom, a movable conveyor mounted in said chamber and co-operating with said outlet from said hopper to receive coal therefrom, a movable brush mounted in said chamber between said air inlet and said outlet for a mixture of coal and air, mechanical means for moving said brush in contact with said conveyor to remove coal from said conveyor and to distribute it in the stream of air passing through said chamber, and means for moving said conveyor.

5. In a pulverized coal burner, the combination of, a hopper for pulverized coal provided with an outlet, a substantially enclosed mixing chamber communicating with said outlet from said hopper and having a regulatable air inlet therein and having an outlet for a mixture of coal and air therefrom, a movable conveyor mounted in said chamber and co-operating with said outlet from said hopper to receive coal from said outlet, a scraper co-operating with said conveyor to remove coal therefrom, a perforated member mounted in said chamber between said air inlet and said outlet for a mixture of coal and air and beneath said scraper to receive coal removed by said scraper, and mechanical means for agitating the coal on said perforated member and for distributing it in the stream of air passing through said chamber.

6. In a pulverized coal burner, the combination of, a hopper for pulverized coal having an exit therefrom, a substantially enclosed mixing chamber communicating with the exit of said hopper and provided with a regulatable air inlet and with an outlet for a mixture of coal and air, a conveyor having a surface to which pulverized coal adheres arranged in said chamber adjacent the exit from said hopper providing a moving wall for removing coal from said hopper, an agitator arranged in said chamber between said inlet and said outlet and co-operating with said conveyor to distribute coal from it in the flow of air in said chamber from said air inlet, means for mechanically agitating said agitator, and means for moving said conveyor.

7. In a pulverized coal burner, the combination of, a hopper for coal dust having an exit therefrom, a substantially enclosed mixing chamber communicating with the exit of the hopper and provided with a regulatable air inlet, and with an outlet for a mixture of coal and air, means arranged in said chamber and adjacent the exit from said hopper providing a moving Wall of rubber-like material to which coal dust adheres for removing coal dust from said hopper, a means arranged in said chamber and contacting with said first means adjacent said air inlet to remove coal dust from said first means and to distribute it in the flow of air in said chamber from said air inlet, and means for moving said first means.

LAURENCE SHUMAN. 

